There is a recognized need for improved neurological research technology since many illnesses originate in the brain. This proposal is for the development of a 24-channel interactive neural probe amplifier system that will specifically be used with neural probes to process signals received from deep brain sites. It will also be capable of transmitting current pulses to stimulate these sites. This signal processing system, with multiple amplifier channels, will be a significant advancement in the state-of-the-art for neurological studies. Currently neuroscientists build their own amplifying systems or manually connect large, commercially available boxes to their probes. Such manual construction leads to non-uniformity and diminished performance. In addition, these handcrafted systems cannot effectively record and stimulate multiple deep brain sites - the exact features many researchers require. This project will investigate compact amplifier designs for connection to a 24-channel deep-brain probe developed in a current SBIR Phase II grant. Consulting neuroscientists will provide significant input to the design. Circuit cards will be manufactured (approximately 0.35" x 1 .1" when fully miniaturized), and a compact ring-array of amplifiers will be formed. In Phase II this interactive neural probe interface will be further miniaturized and additional support equipment will be designed.